My reads on my 2 opponents:
atrisk: passive player, plays any 2 big cards or 2 suited
Yzaki: loves to play aces, folds under pressure very easily

** Palmers Green [Hold em] (0.10|0.20 No Limit - Cash Game) Real Money
- atrisk sitting in seat 1 with $3.43 [Dealer]
- Yzaki sitting in seat 2 with $22.87
- billwadd sitting in seat 3 with $19.80
- yese802 sitting in seat 4 with $19.65
- bdonroyale sitting in seat 5 with $45.80
- Phil1984 sitting in seat 6 with $19.60
Yzaki posted the small blind - $0.10
billwadd posted the big blind - $0.20
** Dealing card to bdonroyale: ,
yese802 folded
bdonroyale raised - $0.80
Phil1984 folded
atrisk called - $0.80
Yzaki called - $0.80
billwadd folded
** Dealing the flop: , ,
Yzaki checked
bdonroyale checked
atrisk checked
** Dealing the turn:
Yzaki bet - $2.45

What do I do now? If I call, I guess I am folding if he leads out on the river, or checking behind if he checks. I probably should have fired out a 1/2 to 3/4 sized probe bet on the flop to see where I stand - at least this way I get any most medium PP to lay it down and deny the odds for a flush. Am I correct here?

Probably fold. He's firing into 2 villians so this reduces the likelyhood that he's bluffing. If it were HU i'd call the turn bet and re-evaluate the river.

I like your flop check.